In the fabrication of semiconductor devices such as integrated circuits, memory cells, and the like, a series of manufacturing operations is performed to define features on semiconductor wafers (“wafers”). These operations are performed in a process chamber supplied with gas at a low pressure. Various voltages, such as RF voltages, are applied to one or more electrodes in the chamber to establish a plasma to perform the operations, including etching and deposition, for example. During these operations, the wafer is held securely in the chamber by an electrostatic chuck (ESC). ESCs are configured with one or more electrodes to which a voltage is applied. The voltage induces charges that urge the wafer against the ECS. Other voltages are applied for separating the wafer from the ESC, an operation known as de-chucking.
During the life of an ESC, repeated application of these applied voltages tends to deteriorate the ESC. As a result, particles of the ESC may flake off the ESC and become loose in the chamber. The plasma may also be a source of particles. As semiconductor integrated circuit technology transitions to sub-100 nanometer scale manufacturing, the presence of undesired particles in such chambers becomes more of a problem, by reducing yields, for example.
In view of the forgoing, there is a need for reducing the amount of particles in the chamber, including reducing the amount of particles that may settle on the wafer during a de-chucking operation.